Avoiding singularities

[RoboticsMan]

Im working on a project, where a KUKA robot is picking unstructured objects from a palletbox. When the robot moves the gripper down into the box in LINEAR mode, there is a risk of singularity, since the arm is straightened out in some situations. Fortunately the KUKA robot has an option which allows it to move through singularities. It simply slows down while it is going through the singularity, and speeds up when it has gone through the singularity. In the future we might also use Kawasaki robots in our installations, so my question is: Do Kawasaki robots also have the ability of going through singularities without stopping because of joint speed limits? And if so, how is this functionality activated and used? I have a Kawasaki robot at my disposal, so if I can get any hints, I will be able to experiment with it...

Thanks in advance!

[wraith]

I think KAWASAKI doesn't provide such option. Is it impossible to analyze robot trajectory while programming to avoid singularities?

[RoboticsMan]

We have strategies designed to avoid singularities, but we would much prefer to move right throught the singularites, since the strategies give us other problems.

[wraith]

Does JOINT mode gives your additional problems?

[RoboticsMan]

Unfortunately joint mode is not an option, it will give us a lot of other problems.

[Kōkaku kidōtai]

Hi,

I don't know if you already solved your problem with singularities, but there is one software option from Kawasaki which may be helpful. It's called SINGULAR POINT MOTION and it's a free software option. In order to unlock it in Kawasaki controller you must get some unlocking file from your Kawasaki supplier.

I attach short description of this function (its number in Kawasaki documentation is ESS453).

Good Luck!

[RoboticsMan]

Thanks!

That might be exactly what Im looking for 

[asimo]

Hi RoboticsMan,

I would like to know what is this option with a Kuka robot? How do you enable it? Is it a package option?

Thanks.

[RoboticsMan]

If you want to avoid stops at jacobian singularities, you must set the value of the variable '$CP_VEL_TYPE' to '#VAR_ALL' in the “KRC\STEU\Mada\$custom.dat” file on the robot.
Note that this will make the robot move slower in some situations.

Good luck!

[asimo]

Thanks a lot for your information RoboticsMan, I'll give it a try.

Cheers